Scanlab RTC6 PCIe Board - Laseron Delay; Laseroff Delay

RTC6 boards
Doc. Rev. 1.0.21 en-US
7 Basic Functions for Scan Head Control and Laser Control
146
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LaserOn Delay
The LaserOn Delay is automatically inserted at the
start of a single Mark Command and at the start of a
series of Mark Command (“Polyline”) and delays the
switching on of the laser.
It can be used for several purposes:
• At the beginning of a marking, the mirrors must
be accelerated to the specified mark speed (if
necessary, from a halt), see Figure 37. This phase
can be suppressed with a sufficiently high
positive LaserOn Delay value until the mirrors
have already reached a certain angular speed
before the laser is switched on. On the other
hand, the LaserOn Delay must not be too long,
otherwise the first part of the marking is cut off.
• Some materials/applications (for example,
welding) take some time until they react as
desired to the exposure to laser radiation. In this
case, it can be useful to “preheat“ the starting
point of the marking. This can be achieved by
setting a negative LaserOn Delay value.
However, this extends the total marking time
because the LaserOn Delay is inserted prior to the
current Mark Command as scanner delay.
(1)
LaserOff Delay
The end of a marking is not defined by the marking
itself, but by the first “normal” list command that is
not a Mark Command, for example, a
Jump Command.
The acceleration phase at the beginning of a
movement leads to a time difference between the
respective set position and the actual position of the
mirrors, see Figure 37.
The laser is to be switched off until the actual value
of the end position is reached (but not already at the
set position). Therefore, a LaserOff Delay is
inserted
(2)
automatically after the end of each
marking by the first “normal” list command (no
“short” list command), see also Section ”Notes”,
page 149. This can be used to compensate for the
Tracking Error of the scan head.
(1) This scanner delay is automatically extended, if a
preceding LaserOff Delay has not yet been expired, see
Section ”Automatic Delay Adjustments”, page 155.
(2) In DSP mode < 3 (see set_dsp_mode), the following
applies for short marking vectors: if a preceding
LaserOn Delay has not yet been expired,
the LaserOff Delay is temporarily automatically
extended accordingly, see Section ”Automatic Delay
Adjustments”, page 155.